Ferrets become sexually mature by six to nine months of age. Your veterinarian should discuss spay/neuter surgery with you before your pet reaches this age.
Potential health problems associated with intact male ferrets become evident at an age later in life. For example, testicular cancers in the ferret have been reported, but if caught early in the disease process, neutering the affected ferret will eliminate the problem.
For the intact female ferret, potentially life-threatening diseases are likely to occur as she goes through the estrus (heat) cycle. Female ferrets are induced ovulators; that is, they will begin a heat cycle and remain in heat until they are bred or induced to ovulate. As a ferret begins a heat cycle, the estrogen level rises and continues to do so for up to six months.
The disease associated with this process is called "hyperestrogenism." The rising estrogen hormone concentration in the blood can induce toxic changes in the bone marrow and destroy the normal bone marrow tissue. Bone marrow in mammals is the site of red and white blood cell production. The more these cells are damaged, the less normal red and white blood cells will be produced. The ferret then develops a severe anemia and white blood cell deficiencies. Because white blood cells are a significant part of the immune system and help fight infection, the ferret is then susceptible to secondary infections due to a weakened immune system. If not detected early, these ferrets will become progressively weak and most will die within 4-6 months.
Any female ferret in heat for one month or more is susceptible to developing this highly fatal disease. Physical signs early in the course of this disease process are generalized weakness, decreased appetite, weight loss, hair loss over the hindquarters and an enlarged vulva. Any of these symptoms should alert you to a potentially serious problem and you should make sure your ferret is seen by a veterinarian familiar with ferrets.
These problems are all avoidable by spaying your female ferret before she becomes sexually mature or by 6 months of age. Spay and neuter surgeries for ferrets are routine for veterinarians familiar with these animals. A physical examination should be performed prior to surgery, along with necessary bloodwork. In general, ferrets do well with the anesthetics used commonly in practice. Following the spay/neuter surgery, your pet should have restricted activity for approximately one week.
Ferrets make wonderful pets, but as with any pet brought into a home, you should research the recommended care through the lifetime of that animal. If you are considering opening your home to a ferret, then spaying/neutering that potential pet should be a part of that responsibility.